Why did not the judge respond last contest?

mafattah · Post by **mafattah** » Sun Sep 15, 2002 4:17 pm

We joined last contest (held last Friday), and we started solving problems. The first two hours the judge worked well, but afterwards, the judge made no reply whatsoever to our submissions, even not the reply of 'Program received'. What is the reason that happened? This is not the first time this happens to us.

The strange thing is that, when I saw the judge status, it was still working, and the ranklist still moving. I tried to send using several mail accounts and using submit-o-matic, and even using different servers to connect from, but got no reply at all.

Did anybody face the same problem? and does anybody know what caused the problem at all?

Picard · Post by **Picard** » Sun Sep 15, 2002 4:49 pm

email timing is unpredictable, it has no timing guarantees especially in a high traffic enviroment. i don't think it's the right method to communicate online in situations like these contests.

i was very happy about the subomatic form. it's much more reliable, you can be sure that your submission reached the web server (although the web can crash and lose contact with the judge, but there is something very wrong when the web interface doesn't work). it can still take quite a while still your submission get in the queue and processed. i never wait for an answer email because it's as unreliable as sending submissions in email. i have an open explorer window for judge status and contest result pages which are updated automaticly and show all information i need (question if the web server can halt the high traffic when everybody ask for these pages)

Ivan Golubev · Post by **Ivan Golubev** » Sun Sep 15, 2002 5:11 pm

Yeah, I've also faced this problem. After I got NaN running time for one problem all my attempts to submit any problem has failed. But after contest I received several replies from the judge, it says 'Out of contest time'. Very nice...

Yarin · Post by **Yarin** » Sun Sep 15, 2002 5:55 pm

Yes, I also had problem after about 2h to send emails (I also sent a mail to clarify@acm.uva.es which didn't get there until after the contest), but the submit-o-matic works great. I think it's unfortunate that the page says "Do not rely on it for serious submissions", during an online contest it seems to be much more reliable (and I've never had problems with the submit-o-matic yet)!

I think the contest page should somewhere mention the submit-o-matic, and have a link to it.

mafattah · Post by **mafattah** » Mon Sep 16, 2002 11:25 am

I actually faced this situation three consecutive times till now, which makes me wonder if there is a solution, as I am nearly never able to enter a contest from the beginning till the end. The strangest thing about this is that the judge continues to correct problems of other people while not receiving mine. One of my friends even was able to get his problem corrected at the same time I faced this problem, which proves that the problems were not delivered late to the judge. I do not think it is a problem of email reliablility, as I tried submit-o-matic also and it did not work.

cytse · Post by **cytse** » Mon Sep 16, 2002 2:54 pm

I faced the same problem. I used submit-o-matic to submit programs, but there were no response from the judge, so I submitted again and again. On average it took me about 20 minutes to make one successful submission, and I got lots of "Out of contest time" after the contest.

Post by **judge** » Mon Sep 16, 2002 3:45 pm

Right now submit-o-matic just sends an email to the judge, so in this way we "skip" Internet and send the email from one account to another one within our system. I know that this is not the best approach as we relay on the email system and we suspect that email system cannot handle such quantity of emails properly, and we know what should be done to avoid email system when submit-o-matic-ing. Don't say anything more about this: we know it must be changed and we'll do as soon as we can.

Post by **judge** » Mon Sep 16, 2002 3:59 pm

BTW, the reason for this may be that the system load was ~20/25 in the last hour - and it seems to be so much, because we have had more than 50 programs waiting to compile... We cannot do anything about this right now, because we have only one server which hosts web, board, judge, email... We receive more than 2,250 submissions a day = 93 submissions an hour if they were in a constant rate - which is false. In contest we can receive more than 10 submissions in a minute in addition to the 24-hours judge, and also more than 80 people browsing our website and a lot of emails (email replies) have to be sent... it seems to be just too much.